Internal-combustion engine



E. L. WRENTMORE INTERNAL COMBUSTION ENGINE March 31. 1925.

Filed March 26, 1919 5 sheets-sheet 1 March 31. 1925i-4 mmuml 1,531,430 E. L. WRENTMORE l INTERNAL coMBUsTloN ENGINE 'Fiied March 2e, 1919 5 sheets-sheet 2 6km, s

March 31. 1925.

A 1,531,430 E. L. WRENTMORE INTERNAL COMBUSTION ENGINE Filedmarch 26, 1919 5 Sheets-Sheet 3 dnn, 5

March 3l. 1925.

E. WRENTMORE INTERNAL COMBUSTION ENGINE Filed March 2s, 1919 5 sheets-sheet 4 s 17%"/l/l/I/l/l//l/l/l/l//l/ Qlil\\\ IIHIIIIIIIIIIllmgllllllllllllllllll l .EMESTLWMNTNDRQ WWW-AM March 31. 1925.

E. LfwRENTMoRE INTERNAL COMBUSTION ENGINE 5 sheets-sheet 5 Filed Mrch 26, 1919 ESTLVMPENTMUJP:

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' uNiTl-:D STATES' maar L. wmmronn, or Wannen, omo, (uns.) mann v. lWmaurrmmn, Ammi- Mmmm or sain ERNEST L. wnnn'rxonn, nnmsnn.

INTERNAL-COMBUSTION ENGINE.

Application ma kann 2e, 1919. sensu no. 2,115,197.

To aZZ whom #may con-cern:

Be it known that I, ERNESTv L. WrunrT-` Morue, citizen of the United States, residing at Warren, in the county of Trumbull an State of Ohio, have invented certain lnew and useful Improvements in an Internal- Combustion Engine, of vwhich the following is a specification.

divergence relatively to the crank axis as the cylinders, and in which two .pairs of cylin ers are grouped in oblique relation to each other and the main crank axis.

This aggroupment of cylinders involves other features of novelty and utility which in general consist in the detailed body con-r structionof the engine and in the valves and valveeoperating mechanism, al1 as` herev inafter shown and described and more particularl pointed out in the claims.

In t e drawings forming part of this application, Fi 1 is a vertical section transversely of e engine on line 1 1, Fig. 2, showing the first pair of pistons 'at thelr extreme outward osition and with their respective connectlng rod pivots on -a straight line with the main crank-axis. Fig. 2 is a vertical sectionV longitudinally' through the engine on line 2 2, Fig. 1, showing the relative working positions of the pistons in full lines inthe cylinders in section, and in dotted lines in the ycylinders located on the far side of the crank shaft axis. Fig. 3 is a bottom view of the removable head for the engine, the head being invertedfto show the. valves and the inner forked ends of the push rods which are engaged by the cams. Fig. 4 is a top lan view of the main body of,the engine as 1t appears with the head removed and show- 1 ing the central channel and cam shaft in the channel. Fig. 5 is a horizontal section of the head on line 5 5, Fig. 2, showing the ment of the cylinders, cylinder to cylinder,

and the zig-zag arrangementof the c linders, air to pair, and the grouping o the cylin ers, four to each group. Fig. 7 is a bottom view of the main body of the engine as it appears inverted without its working parts exce t the crank shaft, which is shown opposite t e cylinder openin to illustrate the shape of the crank shas and the aggroupment of cylinders-whereby one or more of the cylinder ends may be uncovered and ,the pistons freely withdrawn without interference with the crank shaft. Fig. 8 is an end view of the upper part of the engine,

and Fig. 9 is ay vertical section on the center line 9 9, Fig. 8, showin the cam shaft and push rod construction. ig. 10 is a top plan view of one end portion of the engine, and

Fig. 11 is a sectional view of one of the rockarms for actuating the engine valves.

As shown, -the main body of the engine comprises eight cylinders cast en bloc with a dependin skirtin v'2 which is 4rounded or entende outwar ly at its lower end/ to g'vlde the upper half 3 of a ycrank casing.

e lower 'half of the crank casing is a separate removable part in the form of a circular oil pan 4 having a beveled seat 5 for a beveled lip 6 at the inner edge of the upper vhalf 3 of the casing, whereby a Huidtight joint may be obtained withI a. minimum number of bolts or screws 7 see Fig. 1. In an eight cylinder engine constructed according to my invention, the main body of the engine lis divided' transversely into two main groups. of cylinders' arranged at four cylinders to a group. Each groupof four cylinders is subdivided into two pairs of cylinders, and the two cylinders com-` prising each pair are adjacently located but on opposite sides of a crank-shaft 8 common to `all the cylinders. All the cylinders ,9 on one side of the crank shaft are in-- `ifcllned reversely to the cylinders 10 on the opposite side and-the angle of inclination to the perpendicular center line of the en-j gine is relatively slight. Preferably, the cylinders diverge at' an angle of about twenty-two and one-half degrees, and the cranks or wrist pins foreach pair of diverging c linders are also spaced apart the same an ar degree, from center to center, as the c linders, which in the present showing is twent two and one-half de ees. In other wor the paired cylinders 9 and 10,

their com lementary set of cranks or wrlst, ins to w ich their pistons 12 are connecte by rods 14, diverge'or are spaced apart Iin the same angular degree so 'that when both pistons are atthe extreme endv of their strokes the res ctive connecting rods are each' on a stralght line with the mam crank axis whereV astraight line drawn 'throu h the axis of each cyhnder and piston t erein will bisect the center of its 'crank pin and also the main crank axis as seen in Fig. 1. One result of this arrangement of parts is that the pistons for each pair of cylinders move in unison and Without variation in stroke throughout the full cycle of revolution of the crank shaft, and

e two pistons will move inthe same direction and the same distance from their respective c linder heads and reverse simul taneously cause both their connecting rods are thrown out of line with their res ective pistons coincidently and in the saine egree. l

The reciprocal movements of both plstons being identical and never 'varying' aperfect balance between thetwo plstons of any pair of pistons is maintained throughout each revolution of the crank-shaft, and

as a consequence the strainon the double Wrist pin is also, practically uniform and without a torsional eiect as would be imposed by two pistons reversing and moving in opposite''direct-ions.` f

'The angle of divergence of the wrist pins and cylinders being relatively small and the stroke ofthe pistons relatively long the cylinders 9 and 10 comprising each pair are not set directly opposite each other but are odset longitudinally of the crank-shaft and lie in overlapping relations, and lthe axial centers of the cylinders are just far enough apart longitudinally of the crank shaft to permit a straight connecting rod 14 to be used for each piston with the rods of each pair of such related cylinders in relatively 'close proximity and disposed between two long crank arms on the crank-shaft.

The small angle of divergence and offset relatio'n of the paired cylinders also narrows the engine materially at its upper end with very little side overhang, which makes the structure compact and stable, and the respective head ends of each pair of cylinders major part of the oil back into the casin from only one sidethe bottom incline sides of the cylinders. The sli ht divergence of the Wrist pins and paire cylinders and their offset relation also make it possible to remove the istons from the lowerv open ends of the /c inders -when their connecting rods 'are disconnected from the cranks but without removing the crank-shaft from V its bearings. That'is, the crank shaft may be turned in Aits bearings and the wrist pins and crank arms placed opposite the lower end of any cylinder so that ample. clearance is obtained to withdraw thevpiston after its rod has been disconnected yfronnthe crank,

and Fig. 7 shows `a bottom View of the eny gine with the crank case open and the crankshaft in such clearance relation with thev first and third cylinders from the right end thereof. The remaining cylinders are also adapted to be uncovered singly or in pairs by turning the crank-shaft and placing the vwrist-pins and inclined crank-arms in s1rn1- lar clearing relation, thus permitting any single piston or all of them to be removed without removing the crank-shaft.

By inclining and osetting a pair of v cylinders as described, successive pairs of suchcylinders may be used in angular relation to build up a motor consisting of four, or an multiple of four cylinders, and the cylin ers are preferably seggrqgated in groups of four with each pair of cylinders arranged obliquely to the crank axis and angularly-related in zig-zag fashion lto .in each revolution of the crank lshaft one pair` of pistons travel togetherin unison in one direction, while the adjoining pair travel in unison in the opposite direction. In an eight-cylinder engine, Where two groups of four cylinders each are used, the second group is arranged in the same way as the irst group, but the cranks for the second-group are quartered or set at an angle of ninety degrees in respect to the cranks of the first group, thereby permitting a firing operation at each quarter revolution of the crank shaft; and firing may occur successively, first in one cylinder in one group andthen on the opposite side'of the crank shaft in a cylinder of the next group. The spark-plugs 18 for firing purposes are posite a compression space 19 for each cyladapted to be screwed at an angle into suitf ;able bosses at each side of the head 17 opangle to and Abe ond the sides of the head they may be easi y inserted or removed `and the connections conveniently made and in-4 spected from the sides of a car.

The staggered or zig-zag arrangement of cylinders affords ample room for relatively large ducts 20-21 transversely within the cast cylinder head 17 in theangle between the successive pairs of cylinders, and branch channels 22 connect each duct with separate valve ports which open into the compression spaces 19 ofthe cylinders. Each cylinder is thus provided with an inlet and exhaust port, 23 and 24, respectively which communicates with the separate ducts 20 and 21 respectively, and the inlet ducts 20 have their intake ends on one side of the en 'ne for joint connection with a single mani old 25, and the exhaust ducts 21 have outlets on the opposite side of the engine for a similar connection with a manifold 26. This gives an equal distribution of fuel to cach cylinder and a common exhaust for all the cylinders, and the, branch channels are a so curved at their point of union with thc transverse ducts to more eifedtiviel distribute the fuel and to sweep out t e exhaust freely. i

The inlet and exhaust valves 27 and 28, respectively, for each cylinder have seats in the bottom of the removable head, and the stem 29 of each valve extends parallel with the inclined axis of the cylinder and projects throu h the top of the head. The outer end o each valve stem extends through an opening in the outer end of the long arm 30 of a rock member which is sleeved on a shaft 31 extendin longitudinally at. the center and top of t e head. Coiled springs seated in cupped washers -bear against the to'p and bottom of said arm and separate adjusting and lock nuts on the stem regulate the tension of the springs and establish a working connection which is sutliciently lexible to render the operation of the parts noiseless. Each rock member also embodies a perforated short arm on the opposite side of the shaft 31, through which the upper end of a push rod 33 projects, and this rod extends through' the head at the same inclination-to the perpendicular as the cylinder lying beneath the short arm. The lower end of the push rod is adapted to straddle andvengage a cam'34 on cam shaft 15, and a noiseless working connection between the upper end of said push rod and the short arm of the rock member is obtained by means of an adjustable cap nut and a coiled spring bearing upon the upper side of said arm, together w1t-h a rounded nut locked in-working engagement within the rounded socket in theibottom side of said 'short arm. A quick closing movement of the valve is obtained by placing a coiled spring 35 underneath the long arm at apof further advantage in maintaining a constant and practically noiseless working en- Eush rod with the cam. The intake and exaust valves are operated alike but at difgagement of the forked extremity o the ferent intervals necessarily, and the rock A arms are arranged in pairs for each c linder and extend transversely of the hea with the long arms either on one side or the other of the rock-shaft 31, dependent upon the ,i

position of the cylinder.

The cam-shaft 15 is held in removable bearings 36 bolted to the top of the engine body and adapted to be covered by the re-l movable head 17, and one end of the cam shaft extends beyond one end of the engine body and is driven by a train of'gears 37 or equivalent means deriving a rotative movement from the crank shaft, see Fig.Y 2. The body and head of the engine is also suitably cored to provide water 'cooling spaces and to reduce the weight, andthe rock arms above the head may be covered by a light-weight cover or cap if desired, leaving only the spark-plugs exposed for convenient removal and replacement and connection and disconnection of the electric conductors.

What I claim is:

1. 'A plural cylinder engine of the V-type having its cylinders arranged in groups of four, of which the first and fourth cylinders in each group are in one row and the second and third cylinders of said group are in the other row, combined with a crank shaft having its crank pins arranged in groups of two, one associated with a cylinder'in one row and one with a cylinder in the other row, saidcrank pins being circumferentially offset and disposed in diametrical planes which lie at an angle to each other which is the same as the angle between thetwo rows of cylinders.

2. A plural cylinder engine of the having its cylinders arranged in of four, of which the rst and fourth cylinders in each` group are in one row and the second and third cylinders of Said group are in the other row, combined with a crank shaft having its crank pins arranged in pairs which are respectively associated with a pair of cylinders one D1n each row, the two crank pins of each pair being circumferen- V-type tially offset with respect to each other and groups being so placed that when the axis of one crank pin lies in the same plane as the axis of the associated cylinder the axis of the other crank pin of the pair will lie in the same plane as the axis of the cylinder with which it is associated.

3'. A plural cylinder engine of the V-typen having its cylinders arranged in groups of x four,I of which the first and fourth cylinders in each group are in one row and the second and third cylinders of said oup Iare in the other row, the cylinders o one row being arranged with their lower ends overlapping the lower ends of the cylinders of the other row', a single head plate for all of vthe cylinders said head plate containing an inlet passage for each group of four cylinders which inlet passage extends transversely between the yfirst and fourth cylinders of the associated group and has its inlet through that side of the` head plate on which the said first and fourth cylinders lie and which is connected with all of the cylinders of the group of four.

4. A plural cylinder engine of the V-type having its cylinders arranged in groups of four of which the first and fourth cylinders in each group are in one row and the second and'tliird cylinders of said oup are in the other row, the cylinders o one row being arranged with their lower ends overlapping vthe lower ends of the cylinders of the other row, of the cylinders said head rplate containing an inlet passage Vfor each group of four cyl- `inders which inlet passage extends tra-nsversely between the first and fourth cylinders of the associated group and has its inlet through that side of the head plate on which the said first and fourth cylinders lie and which is connected with all of the cylinders ofthe group of four, and saidhead plate having exhaust passages which discharge through the opposite side of the head plate, one of said exhaust passages extending transversely between the two adjacent groups of four cylinders and being connected with two adjacent cylinders of each oup.

gr. A. plural cylinder engine of the V-type having its cylinders arranged in groups of four of which the first and fourth cylinders in each group are in one row and the second and third cylinders of said group are in the other row, the cylinders of one row being arranged with their Ilower ends overlapping the lower ends vof the cylinders of the other row, a single head plate for all of the cylinders said head plate containing an inlet passage for each group of fourcylinders which inlet passage extends transversely between the first and fourth cylinders of the associated vgroup and has its inlet through that side of the head plate on which the said first and fourth cylinders lie and which is connected with all of the a single head plate for all4 cylinders of the group of four,I and said head plate having exhaust passages which discharge through the opposite side of the head plate one of saidexhaust passages eil.-v tending transversely between the two adjacent grou s of four cylinders and bein -connected with two adjacent cylinders o each group, and the other exhaust passages being extended transversely between the ends of the head plate and the adjacent end cylinders and bein respectively connected with the adjacent en cylinders.

In an 8cylinder internal combustion engine in which the cylinders are arranged in two oppositely inclined rows and are associated in such wise that each cylinder in each row is associated with the adjacent cylinder in the opposite row to' form a balanced pair, a single unitary head plate for all of the cylinders spanning the V-space between the two rows, said head plate containing two transversely extended gas inlet passages which open through the same side of the headplate and which are respectivel disposed between the two end pairs of cyfI inders and the two next adjacent pairs of cylinders, each of said gas passages having four branches which respectively communicate with the four cylinders of the two pairs n of cylinders between which it is located, and said head plate also containing three transversely extended exhaust gas passages allv opening through .the op osite side of the head plate, two of said ex iaust gas passages being respectively located beyond the two end pairs of cylinders and each having two branches which` respectively communicate with the adjacent end pair of cylinders, the third exhaust passage being located between the two middle pairs of cylinders and having four branches which res actively cornmunicate with the four cylin ers of the two pairs between which it lies.

7 A plural cylinder en ine of the V-type having two rows of cylinlers spaced angularly with respect to each other, a crank shaft, pistons in said cylinders and connections from the crank shaft to the pistons for causing the pistons to be operated in pairs, one piston of each pair being in one row of cylinders and the other piston of the pair being inthe other row, the` two pistons of each pair moving at all times in unison.

Signed at Warren, in the county of Trumbull, -and State of Ohio, this 21 day of March, 1919.

' ERNEST L. WRENTMORE.

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